A compound expression specifies a combination of other expressions.
You can use any built-in function as an expression ("Function Expressions"). However, in a compound expression, some combinations of functions are inappropriate and are rejected. For example, the LENGTH
function is inappropriate within an aggregate function.
The PRIOR
operator is used in CONNECT
BY
clauses of hierarchical queries.
Some valid compound expressions are:
('CLARK' || 'SMITH') LENGTH('MOOSE') * 57 SQRT(144) + 72 my_fun(TO_CHAR(sysdate,'DD-MMM-YY'))